Thanks for the tip; that's a really cool project. It looks like the documentation generator for it works on a single file at a time, and a single file defines a single service. I was thinking of something that works on the level of a system of interacting services. I want a tool that reads the API specifications for a group of services and documents the interactions between them. I'd like to look at service X and see that it emits message Y on queue Z, and then see which services read message Y on queue Z, jump to their documentation, etc. I think the AsyncAPI format is perfect to build on, though. I'll start there if I decide to take a hack at it.